1 4 Loss uf Lives at Sheriff Hill Colliery, 



mosphere; and not to speak of probability, what proof can be 

 adduced that there was a variation ? 



As to the theory of electric influences, I am at a loss to under- 

 stand upon what basis it is founded. It appears to me to be an 

 adaptation of an hypothetical principle supported by facts which 

 admit of a different explanation equaUy. in short, throughout 

 all the hypotheses of electricity which have come within my 

 limited knowledge, the proofs are derived from the thing to be 

 proved, and have this property, that when the reasonings are 

 pursued in all their evolutions, the inquirer invariably arrives at 

 the place from whence he set out. 



The other principal topic on which Mr. De Luc is not satisfied, 

 is my assertion of the permeability of glass ; and he states that 

 his explanation of the Leyden phial is founded on a supposition 

 of the contrary. Mr. De Luc also declares himself disinclined 

 at this advanced and infirm ]3eriod of his life to undertake any 

 new experiments, but suggests one to me for trial. The least 

 possible return that can be made to a philosopher who has em- 

 ployed a long life in labours so creditable to himself and service- 

 able to the cultivators of science, would be to execute his sug- 

 gestions, but that the circumstances have rendered it unnecessary. 

 Mr. De Luc will find by referring to my first paper on this sub- 

 ject, that I was av/are of the oi)jection, and had ))rovided against 

 it ; he will then probably agree with me that glass is permeable 

 to the electric fluid. 



I have the honour to be, sir, 



Your humble servant, 



Dublin, June Ci, 18 ^5. M. DoNOVAN. 



VL Destriiclion of the Fiewcrs and Overmen at Sheriff Hill 

 Collienj. By A CoRRESpo^.DE^T. 



To Mr. Tilloch. 



SiR, — xxcTUATEi) by the same motive that prompted me to 

 write you an account of the shocking accidents which befel the 

 workmen in Heaton and Nevvbottle colliery a short time since, 

 I now transmit the particulars of an explosion at Sheriff Hill ; 

 not so destructive of human beings as either of those catastro- 

 phes, though highly distressing in its consequences ; for on the 

 present occasion all the managing and experienced miners em- 

 ployed in the cou';ern have lost their lives. The mine at Sheriff 

 Hill is situated on the elevated ground forming the southern 

 banks of the vale of Tyne opposite Newcastle, from whence its 

 dibtance is between two and three miles. Here the low main 



coal 



